1. Field of the Invention
The present invention relates to a resistance change memory device, and in particular, to a memory device having cell array blocks, each including memory cells arranged in a three-dimensional manner.
2. Description of the Related Art
Resistive memory (Resistance RAM; ReRAM), which changes the resistance state of material with voltage, current, heat, etc., and utilizes the resistance state as data, has gained increasing attention as a likely candidate for replacing NAND-type flash memory (see, for example, Y. Hosoi et al, “High Speed Unipolar Switching Resistance RAM (RRAM) Technology” IEEE International Electron Devices Meeting 2006 Technical Digest p. 793-796). The resistance change memory seems to offer a high availability as a large capacity file memory from the viewpoint of its suitability for refinement and lamination, while enabling configuration of cross-point cells.
However, variable resistance elements (resistance change material) that are used as the storage layers of memory cells may have such characteristics that they would not exhibit stable resistance change unless a high voltage is applied thereto. In addition, given that the large capacity file memory is achieved through configuration of cell arrays in a three-dimensional manner, there will be a non-negligible enhancement in leakage current when diodes used as access elements of memory cells are reverse-biased, in addition to a significant increase in the number of waiting cells. Therefore, there is a need for improvements in the accessing scheme taking account the effects of leakage current, and also in the data transfer scheme in order to achieve a faster and larger capacity file memory than the NAND-type flash memory.